feat: show CommitRelationTracking on CommitGraph (#940)

- Add SHA property to the Dot class and assign commit SHA to anchor instances in the CommitGraph model.
- Add constructor to initialize commit relation tracking with repository path and commit hash, enabling querying and displaying related refs while managing loading state.
- Add pointer interaction handlers to the `CommitGraph` class for displaying commit details on click, updating cursor on hover, and resetting cursor on exit.

Author: gadfly3173

src/Models/CommitGraph.cs

@@ -54,6 +54,7 @@ public class Dot
             public Point Center;
             public int Color;
             public bool IsMerged;
+            public string SHA;
         }
 
         public List<Path> Paths { get; } = [];
@@ -149,7 +150,7 @@ public static CommitGraph Parse(List<Commit> commits, bool firstParentOnlyEnable
                 // Calculate link position of this commit.
                 var position = new Point(major?.LastX ?? offsetX, offsetY);
                 var dotColor = major?.Path.Color ?? 0;
-                var anchor = new Dot() { Center = position, Color = dotColor, IsMerged = isMerged };
+                var anchor = new Dot() { Center = position, Color = dotColor, IsMerged = isMerged, SHA = commit.SHA };
                 if (commit.IsCurrentHead)
                     anchor.Type = DotType.Head;
                 else if (commit.Parents.Count > 1)

src/Views/CommitRelationTracking.axaml.cs

@@ -28,5 +28,22 @@ public CommitRelationTracking(ViewModels.CommitDetail detail)
                 });
             });
         }
+
+        public CommitRelationTracking(string repoPath, string commitHash)
+        {
+            InitializeComponent();
+
+            LoadingIcon.IsVisible = true;
+
+            Task.Run(() =>
+            {
+                var containsIn = new Commands.QueryRefsContainsCommit(repoPath, commitHash).Result();
+                Dispatcher.UIThread.Invoke(() =>
+                {
+                    Container.ItemsSource = containsIn;
+                    LoadingIcon.IsVisible = false;
+                });
+            });
+        }
     }
 }

src/Views/Histories.axaml.cs

@@ -520,6 +520,13 @@ static CommitGraph()
             AffectsRender<CommitGraph>(GraphProperty, DotBrushProperty, OnlyHighlightCurrentBranchProperty);
         }
 
+        public CommitGraph()
+        {
+            PointerPressed += OnPointerPressed;
+            PointerMoved += OnPointerMoved;
+            PointerExited += OnPointerExited;
+        }
+
         public override void Render(DrawingContext context)
         {
             base.Render(context);
@@ -705,6 +712,56 @@ private void DrawAnchors(DrawingContext context, Models.CommitGraph graph, doubl
                 }
             }
         }
+
+        private void OnPointerPressed(object sender, PointerPressedEventArgs e)
+        {
+            var point = e.GetPosition(this);
+            var dot = FindDotAtPosition(point);
+            var repoView = this.FindAncestorOfType<Repository>();
+            var repoPath = (repoView?.DataContext as ViewModels.Repository)?.FullPath;
+            if (dot == null || string.IsNullOrEmpty(repoPath))
+                return;
+
+            var tracking = new CommitRelationTracking(repoPath, dot.SHA);
+            var flyout = new Flyout { Content = tracking };
+            flyout.ShowAt(this, true);
+        }
+
+        private void OnPointerMoved(object sender, PointerEventArgs e)
+        {
+            var point = e.GetPosition(this);
+            var dot = FindDotAtPosition(point);
+            Cursor = dot != null ? new Cursor(StandardCursorType.Hand) : new Cursor(StandardCursorType.Arrow);
+        }
+
+        private void OnPointerExited(object sender, PointerEventArgs e)
+        {
+            Cursor = new Cursor(StandardCursorType.Arrow);
+        }
+
+        private Models.CommitGraph.Dot FindDotAtPosition(Point point)
+        {
+            var graph = Graph;
+            if (graph == null)
+                return null;
+
+            // get scroll offset
+            var histories = this.FindAncestorOfType<Histories>();
+            var scrollOffset = histories?.CommitListContainer.Scroll?.Offset.Y ?? 0;
+
+            // adjust point
+            var adjustedPoint = new Point(point.X, point.Y + scrollOffset);
+
+            foreach (var dot in graph.Dots)
+            {
+                var distance = Math.Sqrt(Math.Pow(dot.Center.X - adjustedPoint.X, 2) + Math.Pow(dot.Center.Y - adjustedPoint.Y, 2));
+                if (distance <= 6)
+                {
+                    return dot;
+                }
+            }
+            return null;
+        }
     }
 
     public partial class Histories : UserControl